Video settings

Saving the red-finned blue-eye fish

IT'S always rush hour in Edgbaston's shallow springs. Black bugs and sheer shrimps dart across soft, fine sand at a frenetic pace. The chrome-coloured red-finned blue-eye fish stick together in silent, synchronised schools. When they move, they move with urgency. Frogs launch themselves like rockets. Only snails live life at, well, snail's pace.

Rimmed by native grasses, the vivid pools at this central Queensland nature reserve are bursting with life, some of it endangered, much of it endemic to Edgbaston's unique spring-centric ecosystem.

''Everything that lives at Edgbaston is listed as endangered as part of the ecological community,'' said Bush Heritage aquatic ecologist Adam Kerezsy. Up to 14 snail species, a dragonfly and two nationally threatened fish species are found only here.

Dr Adam Kerezsy: 'We are working with the last few populations.' Photo: Angela Wylie

For generations the 8100 hectare property, 140 kilometres north-east of Longreach, was a cattle station, but in 2008 the flat land spanning the Mitchell Grass Plains and Desert Uplands was purchased by conservation group Bush Heritage.

Advertisement

Next week, Dr Kerezsy's 10-year protection plan for the reserve's most endangered residents - the tiny red-finned blue-eye - will be released after three years of scientific monitoring.

A relic from another era, the freshwater fish's closest relatives live in coastal rivers in northern Australia and Papua New Guinea. ''That tells us its ancestors evolved in Australia when it was much wetter,'' he said. ''When conditions dried, it was stranded and to survive the red-finned blue-eye developed these amazing climatic tolerances.''

In the spring waters at Edgbaston in central Queensland, a program has begun to save the red-finned blue-eye fish from extinction. Photo: Angela Wylie

The shallow springs, which bubble up from the Great Artesian Basin to spread pancake-like across the flat clay ground, became crucial to the tiny fish's survival. Without these pockets of swampy oasis, the arid conditions of central Queensland would have got the better of the small fish long ago.

''They have become artesian springs specialists,'' Dr Kerezsy said. ''And when I say specialists, these guys can survive in water that gets up to 40 degrees in summer and close to zero in winter.''

The silvery fish, with only the males boasting the tell-tale red fins, grow to just 2.5 centimetres long. They survive in slightly salty water as shallow as two centimetres. But the percolating springs that saved the species are also aiding the biggest threat to the red-finned blue-eye.

The endangered red-finned blue-eye at Edgbaston.

Photographer Angela Wylie visited ecologist Dr Adam Kerezsy who is working to save the tiny endangered red-finned blue-eye fish at Edgbaston Reserve in central Queensland, 140 km's NE from Longreach. The fish is only found in this isolated, shallow spring and is being overtaken by the invasive gambusia - or mosquito fish. The old sheep station is an acquired Bush Heritage property.

When the rains come the springs spread, transporting the gambusia. Introduced from America to tackle mosquitoes in the 1920s, gambusia - or ''damnbusia'' as some fish ecologists call them - are master colonisers. They don't just occupy, they infest.

Also known as mosquitofish, they have not only been observed eating larval native species but their own offspring as well. Rather than share the shallows, they nip at the tails and fins of the red-finned blue-eye.

But their main competitive advantage is that their young come out swimming. In contrast, native freshwater fish lay eggs - which soon becomes food for growing gambusia.

The endangered red-finned blue-eye fish. Photo: Angela Wylie

Of the seven red-finned blue-eye populations found when the native fish was accidentally discovered in 1990, just four remained in 2008. There are now three naturally occurring populations, although another three relocated populations exist on the reserve.

''As far as we know we are working with the last few populations,'' Dr Kerezsy said.

Phase one of the protection plan, which Dr Kerezsy hopes will result in 10 gambusia-free populations within a decade, is an earth bund. The recently completed ''great gambusia wall'' is a barrier encircling a spring of about 1000 red-finned blue-eye yet to encounter the aggressive American.

Dr Kerezsy's report will be sent to government agencies in charge of administering future endangered species acts.

''We know things are quite dire for this species but we actually have the power to do something,'' he said. ''And it's so simple. All we have to do is get them the right habitat and make it safe, which means keeping the invasive species out.''

The Saturday Age travelled to Edgbaston Reserve with Bush Heritage Australia.